The aim of the present work was to investigate the synergetic effect of microwave and ultrasound treatment on the production, chemical composition and antioxidant activity of rose essential oil. The rose essential oil...The aim of the present work was to investigate the synergetic effect of microwave and ultrasound treatment on the production, chemical composition and antioxidant activity of rose essential oil. The rose essential oil was extracted from fresh Rosa x damciscena Mill. petals by four methods, hydrodistillation, steam distillation, organic solvent extraction and ultrasounds followed by microwave hydrodistillation. The chemical composition of the extracts was analysed by GC-MS, and the antioxidant capacity by DPPH. It was found that both chemical composition and the antioxidant activity of the extracts depend on the extraction method. Overall it was found that microwaves coupled with ultrasonic treatment can be used effectively for the intensification of the extraction of monoterpenes and sesquiterpenes--fragrance bearing molecules--and equally, for increased antioxidant activity while using about 4 time shorter extraction time. The scale-up of the method was also evaluated. The results obtained in this research support the possible use of the US/MW method for the extraction of rose essential oil for the pharmaceutical and fragrance industry.展开更多
Poor resolution for the identification of endopeptidase(EP) activity in activity gel assays is a critical issue in the analysis of the postharvest physiology of rose petals. In this paper, major factors influencing EP...Poor resolution for the identification of endopeptidase(EP) activity in activity gel assays is a critical issue in the analysis of the postharvest physiology of rose petals. In this paper, major factors influencing EP activity gel assays were evaluated. The results showed that a phosphate(NaH_2PO_4/Na_2HPO_4) buffer favors the detection of clear EP bands, as compared to Tris–HCl buffer. Removal of salts and pigments with Sephadex G-25 columns was vital to the measurement of EP activity in rose petal extracts. For optimal resolution of bands, we show that before electrophoresis,samples should be treated for 10 min at 40 °C. Additionally, electrophoresis should be done in 12% SDS–PAGE co-polymerized with 0.15%(w/v) gelatin. After electrophoresis, the optimal incubation temperature and pH are 42 °C and 7.0, respectively. Using our optimized assay, Rh-EP1,Rh-EP2, Rh-EP3, three proteases with molecular masses of 200, 123.5, and 97.4 kD, respectively, were detected in rose petals. Experiments using EP class-specific inhibitors revealed that Rh-EP2 and Rh-EP3 were both serine proteases, while Rh-EP1 was a metalloprotease. In this study, we also measured changes in EP activity during flower opening, senescence, and water deficit stress(WDS) using our optimized activity gel assay,and found that Rh-EP3 may be more relevant to senescence in roses compared with Rh-EP1 or Rh-EP2. Changes occurring to EPs after WDS were similar to those during the period from flower opening to senescence, and Rh-EP3 activities were greatly increased by WDS treatment. Collectively, our results suggest that significant increases in Rh-EPs activities, especially increases in Rh-EP3 activity, may contribute to the flower senescence induced under WDS treatment.展开更多
以墨红玫瑰花瓣为原料,采用纤维素酶或果胶酶处理墨红玫瑰花瓣,以还原糖含量为指标,通过单因素和响应面试验确定墨红玫瑰花瓣酶解过程中料液比、酶添加量和酶解时间的最佳条件。在此基础上,检测酶解提取对样品抗氧化、弹性蛋白酶抑制活...以墨红玫瑰花瓣为原料,采用纤维素酶或果胶酶处理墨红玫瑰花瓣,以还原糖含量为指标,通过单因素和响应面试验确定墨红玫瑰花瓣酶解过程中料液比、酶添加量和酶解时间的最佳条件。在此基础上,检测酶解提取对样品抗氧化、弹性蛋白酶抑制活性的影响。结果表明,纤维素酶酶解的最佳工艺条件如下:料液比1∶54.20(g/mL),纤维素酶添加量4.00%,提取时间3 h 49 min,所得提取物中还原糖含量达到139.07±1.32 mg/g。果胶酶酶解的最佳工艺条件为料液比1∶61.80(g/mL),酶添加量5.52%,提取时间3 h 12 min,此条件下墨红玫瑰花瓣还原糖含量为122.99±1.14 mg/g。HPLC分析发现2种酶解处理的墨红玫瑰花瓣提取物所含的主要还原糖均为葡萄糖和半乳糖。经酶法处理后获得的墨红玫瑰花瓣提取物的还原糖含量、抗氧化性及弹性蛋白酶抑制力均得到明显提升,为墨红玫瑰花深加工提供理论支持。展开更多
采用热风干燥获得压花用玫瑰花瓣,研究热风干燥温度、时间对玫瑰花瓣干燥特性、压花艺术美观性的影响,采用SEM表征玫瑰花瓣干燥过程表面微观形态特征,以期建立干燥过程动力学模型并计算动力学参数。结果表明,在试验设计温度范围内,热风...采用热风干燥获得压花用玫瑰花瓣,研究热风干燥温度、时间对玫瑰花瓣干燥特性、压花艺术美观性的影响,采用SEM表征玫瑰花瓣干燥过程表面微观形态特征,以期建立干燥过程动力学模型并计算动力学参数。结果表明,在试验设计温度范围内,热风干燥温度越高,时间越长,越有利于降低花瓣的水分,但会降低花瓣的艺术美观性,在热风40℃、840 min下干燥,可以获得具有较好艺术美感的玫瑰花瓣压花材料;干燥过程的有效扩散系数为2.524×10-10m2/s,活化能为11.322 k J/mol,动力学模型可用薄层干燥Page模型来描述。展开更多
采用真空干燥获得玫瑰花瓣压花材料,研究真空度、温度等条件对玫瑰花瓣干燥特性、压花艺术美观性的影响,采用差热-热重(TG-DTG)分析、扫描电镜对玫瑰花瓣热变化过程、表面微观形态进行表征,建立干燥过程动力学模型并计算动力学参数。结...采用真空干燥获得玫瑰花瓣压花材料,研究真空度、温度等条件对玫瑰花瓣干燥特性、压花艺术美观性的影响,采用差热-热重(TG-DTG)分析、扫描电镜对玫瑰花瓣热变化过程、表面微观形态进行表征,建立干燥过程动力学模型并计算动力学参数。结果表明,温度越高,真空度越大,玫瑰花瓣的干燥越快,但温度过高,玫瑰花瓣的艺术美观性下降,在真空度0.1MPa、45℃、30 min下干燥,可以获得具有较好艺术美感的玫瑰花瓣压花材料。真空干燥下,玫瑰花瓣正面原阵列状的乳突结构和反面的沟回结构逐渐收缩,导致正面乳突腔体塌陷,反面形成浮雕状突起。干燥过程的有效扩散系数为8.119×10-9m2/s,活化能为10.045 k J/mol,动力学模型可用薄层干燥Wang and Singh模型来描述。展开更多
文摘The aim of the present work was to investigate the synergetic effect of microwave and ultrasound treatment on the production, chemical composition and antioxidant activity of rose essential oil. The rose essential oil was extracted from fresh Rosa x damciscena Mill. petals by four methods, hydrodistillation, steam distillation, organic solvent extraction and ultrasounds followed by microwave hydrodistillation. The chemical composition of the extracts was analysed by GC-MS, and the antioxidant capacity by DPPH. It was found that both chemical composition and the antioxidant activity of the extracts depend on the extraction method. Overall it was found that microwaves coupled with ultrasonic treatment can be used effectively for the intensification of the extraction of monoterpenes and sesquiterpenes--fragrance bearing molecules--and equally, for increased antioxidant activity while using about 4 time shorter extraction time. The scale-up of the method was also evaluated. The results obtained in this research support the possible use of the US/MW method for the extraction of rose essential oil for the pharmaceutical and fragrance industry.
基金supported by grants from the National Natural Science Foundation of China(30972025,31372105)
文摘Poor resolution for the identification of endopeptidase(EP) activity in activity gel assays is a critical issue in the analysis of the postharvest physiology of rose petals. In this paper, major factors influencing EP activity gel assays were evaluated. The results showed that a phosphate(NaH_2PO_4/Na_2HPO_4) buffer favors the detection of clear EP bands, as compared to Tris–HCl buffer. Removal of salts and pigments with Sephadex G-25 columns was vital to the measurement of EP activity in rose petal extracts. For optimal resolution of bands, we show that before electrophoresis,samples should be treated for 10 min at 40 °C. Additionally, electrophoresis should be done in 12% SDS–PAGE co-polymerized with 0.15%(w/v) gelatin. After electrophoresis, the optimal incubation temperature and pH are 42 °C and 7.0, respectively. Using our optimized assay, Rh-EP1,Rh-EP2, Rh-EP3, three proteases with molecular masses of 200, 123.5, and 97.4 kD, respectively, were detected in rose petals. Experiments using EP class-specific inhibitors revealed that Rh-EP2 and Rh-EP3 were both serine proteases, while Rh-EP1 was a metalloprotease. In this study, we also measured changes in EP activity during flower opening, senescence, and water deficit stress(WDS) using our optimized activity gel assay,and found that Rh-EP3 may be more relevant to senescence in roses compared with Rh-EP1 or Rh-EP2. Changes occurring to EPs after WDS were similar to those during the period from flower opening to senescence, and Rh-EP3 activities were greatly increased by WDS treatment. Collectively, our results suggest that significant increases in Rh-EPs activities, especially increases in Rh-EP3 activity, may contribute to the flower senescence induced under WDS treatment.
文摘以墨红玫瑰花瓣为原料,采用纤维素酶或果胶酶处理墨红玫瑰花瓣,以还原糖含量为指标,通过单因素和响应面试验确定墨红玫瑰花瓣酶解过程中料液比、酶添加量和酶解时间的最佳条件。在此基础上,检测酶解提取对样品抗氧化、弹性蛋白酶抑制活性的影响。结果表明,纤维素酶酶解的最佳工艺条件如下:料液比1∶54.20(g/mL),纤维素酶添加量4.00%,提取时间3 h 49 min,所得提取物中还原糖含量达到139.07±1.32 mg/g。果胶酶酶解的最佳工艺条件为料液比1∶61.80(g/mL),酶添加量5.52%,提取时间3 h 12 min,此条件下墨红玫瑰花瓣还原糖含量为122.99±1.14 mg/g。HPLC分析发现2种酶解处理的墨红玫瑰花瓣提取物所含的主要还原糖均为葡萄糖和半乳糖。经酶法处理后获得的墨红玫瑰花瓣提取物的还原糖含量、抗氧化性及弹性蛋白酶抑制力均得到明显提升,为墨红玫瑰花深加工提供理论支持。
文摘采用热风干燥获得压花用玫瑰花瓣,研究热风干燥温度、时间对玫瑰花瓣干燥特性、压花艺术美观性的影响,采用SEM表征玫瑰花瓣干燥过程表面微观形态特征,以期建立干燥过程动力学模型并计算动力学参数。结果表明,在试验设计温度范围内,热风干燥温度越高,时间越长,越有利于降低花瓣的水分,但会降低花瓣的艺术美观性,在热风40℃、840 min下干燥,可以获得具有较好艺术美感的玫瑰花瓣压花材料;干燥过程的有效扩散系数为2.524×10-10m2/s,活化能为11.322 k J/mol,动力学模型可用薄层干燥Page模型来描述。
文摘采用真空干燥获得玫瑰花瓣压花材料,研究真空度、温度等条件对玫瑰花瓣干燥特性、压花艺术美观性的影响,采用差热-热重(TG-DTG)分析、扫描电镜对玫瑰花瓣热变化过程、表面微观形态进行表征,建立干燥过程动力学模型并计算动力学参数。结果表明,温度越高,真空度越大,玫瑰花瓣的干燥越快,但温度过高,玫瑰花瓣的艺术美观性下降,在真空度0.1MPa、45℃、30 min下干燥,可以获得具有较好艺术美感的玫瑰花瓣压花材料。真空干燥下,玫瑰花瓣正面原阵列状的乳突结构和反面的沟回结构逐渐收缩,导致正面乳突腔体塌陷,反面形成浮雕状突起。干燥过程的有效扩散系数为8.119×10-9m2/s,活化能为10.045 k J/mol,动力学模型可用薄层干燥Wang and Singh模型来描述。
